Lubricating oils thickened with metal salts of cyanuric acid



United States Patent 2,830,020 LUIRICA'IING OILS THICKENED WITH METAL SALTS F CYANURIC ACID Ludwig I. Chrlstmann, Bronxvllle, and William G.

Delchert, Flushing, N. Y., or; to American Cyanamld Company, New York, N. Y., a corporation of No Drawing. Application October 1,1956 Serial No. 612,955

Claims. (Cl. 252-436) and are generally grouped into three classes: (1) act-- mixturesof oils and solid lubricants such as graphite, mica, talc, etc.; (2) blend s of residuum, waxes, uncombined fats, rosin oils, etc.; and (3) soap-thickened oils normally comprising oils and added thickening agents,

such as the sodium, calcium, aluminum orlead soaps of fatty acids. I This latter class of soap-thickened oils is commercially very important and verywidely used industrially inasmuch as a large variety of greases of different consistencies, properties and characteristics can be produced by selecting a particular metal, a particular mixture of fatty or similar acids and a partciular oil stock.

It has been found that salts of cyanuric acid are excellent thickening agents and, when added to oils, will thicken the same to form greases capable of use not only as general-purpose lubricants for bearings, journals, lineshafting and the like but also applicable under a wide range of varying temperature conditions and of particular use at elevated temperatures. These salts further find utility as thickening agents in general for materials such as alcohols and other inflammables in the manufacture of Sterno or like products.

Illustrative of the salts of cyanuric acid which have been found applicable as grease thickening agents are the alkali metal salts notably sodium and potassium, the alkaline earth metal salts notably calcium and magnesium, the heavy metal salts notably zinc and aluminum, the ammonium salts, and the amine salts such as ethylamine, diethylamine, triethylamine, propylamine, ethanolamine, aniline, morpholine, pyridine, eyelohexylamine, etc. It is also to be appreciated that the term salts" includes the mono-, diand tri-salts of cyanuric acid, as well as mixtures thereof, resulting from the reaction of the cyanuric acid and the particular basic salt-forming material used and dependent upon the molal proportions employed.

The materials to which these .salts of cyanuric acid are added have been referred to as oils but it is to be appreciated that this term is not limited to the narrow interpretation thereof but is intended to cover all oily or oleaginous materials capable of use as lubricants or I as greases when compounded with the salts of cyanuric acid.

These oleaginous materials would consequently in- 4 elude: (1) the petroleum hydrocarbon mineral lubricat- 2,830,020 Patented Apr. 8, 1 958 thetic lubricants such as diesters of glycol, diesters of aliphatic and aromatic dibasic acids notably bis(2-ethyl hexyl)sebacate and bis(2-ethylhexyl phthalate), triesters of phosphoric acid, etc.; (5) the silicone oils (siloxanes) having viscosities of from about 40 to about 1000 centistokes at 100 R, such as methyl silicones, methyl phenyl silicones, phenyl silicones, etc.; and (6) the fluorine-derivative synthetic lubricants (fluorocarbons) such as tertiary amines, ethers and esters, the alkyl or aryl groups of which have been fluorinated.

The amounts or concentrations of the salts of cyanuric acid to be included in the oleaginous materials for thickening purposes will naturally vary as to the specific nature of the salt and the oil themselves, the nature and intended purpose and use of the resulting grease, the

.properties and characteristics desired, etc. It has been found that from about 3 percent to about 20 percent by weight is an etfective range, with from about 7 percent to about 12 percent by weight being the commercially preferred range.

The salts may be compounded with the oils by a simple addition thereto with stirring at room or elevated temperature. If a smoother grease is desired, milling of the salt may be resorted to, prior to its incorporation into the oil. The resulting greases range from semisoft and buttery in texture to smooth, thick, viscous, firm and semi-solid.

The invention will be further illustrated in more specfic detail by the following tests and related examples. It should be understood, however, that although these tests and examples may describe in more particular detail some of the very specific features of the invention, they are given primarily for purposes of illustration and the invention in its broader aspects is not to be construed as limited thereto.

EXAMPLE 1 through a Buchner funnel. Slurry the filter cake in about 25 liters of n-propanol and distill ofi liquid (azeotrope) until the volume of the liquid in the distillation flask is reduced to about 12.5 liters. (Final temperature about 90 C.) Filter this slurry remaining in the distillation flask through a Buchner funnel and then dry the product at 80-90 C. for 4-5 hoursin an oven which provides for safe removal of the evaporated liquid.

Evaluation No. 1

The thickening properties of the sodium cyanurate prepared in Example 1 were evaluated in a silicone fluid as follows: 10 grams of sodium cyanurate was dispersed, with stirring, in 100 cc. of SF-96 (200) silicone fluid having a viscosity of 200 centistokes or 912 S. S. U. at

100' F. This fluid originally had a density of 8 lbs. per gallon, a pour point of about -60 F. and a flash point of about 600 F.

The addition of the sodium cyanurate thickened the silicone oil to a semi-solid grease-like consistency which was then tested according to ASTM specifications, D217- 52T, as described in part 5, ASTM standards, 1952, pages 119-128. The results-of the penetrometer tests were as follows: 1

Penetration (unworked) 320 mm./ 10 Penetration (worked 60 strokes) 333 mm./ 10 Penetration (worked 120 strokes) 339 mm./l0

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Evaluation No. 2

A grease was prepared by incorporating 6 grams of sodium cyanurate (Example 1) in SF-96 (1000) silicone fluid having a viscosity of 1000 centistokes or 4620 S. S. U. at 100 F. The density of this fluid originally was 8 lbs. per gallon, its pour point was below 5.7' F. audits flash point was above 600 F. The addition of the sodium cyanurate thickened the silicone fluid into a semisolid grease which could be inverted when in an open container without pouring or flowing. This consistency of the composition was sufliciently thick. and viscous as to render it suitable for grease purposes.

Evaluation No. 3

A grease was prepared by incorporating 3 grams of sodium cyanurate (Example 1) in SF-96 (1000) silicone fluid having a viscosity of 1000 centistokes or. 4620 S. S. U. at 1007 F. The density of this fluid was 8 lbs. per gallon, its pour point was below 57 F. and its flash point was above 600 F. The addition of the sodium cyanurate thickened the silicone fluid into a firm grease which was sufliciently thick and viscous as to render it suitable for grease purposes.

Evaluation No. 4

20 grams of sodium cyanurate (Example!) was added, l

with stirring, to 100 cc. of an ester synthetic lubricant consisting of dioctyl sebacate. The dioctyl sebacate was very thin originally and had almost a watery consistency. The addition of the sodium cyanurate thickened the dioctyl sebacate so that it had the consistency of a light cold cream and was suitable for use as a grease.

Evaluation N0. 5

16 grams of sodium cyanurate was added to a polyglycol synthetic lubricant (polyethylene oxide, UCC Ucon Lubricant LB-300X, water insoluble) and thickened the same so that it was semi-solid and would not flow. Its consistency was sufiiciently heavy and viscous as to render it useful as a grease.

EXAMPLE 2 Lithium cyanurate was prepared by dispersing 28.4 grams of 91% cyanuric acid in 150 ml. of water, adding 16.8 grams of LiOH.2H,O in 100 ml. of water in a steady stream with agitation, and heating. The mixture was heated to 100" C., allowed to cool to room temperature and vacuum filtered. The filtrate was again heated to 100' C. under a reflux condenser, theheat was turned of,

and 500 ml. of ethanol preheated to 75 C. was added slowly. The resulting precipitate was vacuum filtered and the filter cake slurried in 600 ml. of ethanol and again filtered. The lithium cyanurate filter cake was again slurried in 600 ml. of ethanol and dehydrated by distilling with agitation to a head-temperature of 78'. C. It was vacuum filtered, air-dried, and further dried in a hot-air oven at 75 F. for 12 hours.

A grease having a penetration range of 325-340 mm./l0 was prepared by mixing '10 parts by weight of the dried lithium cyanurate with parts of the SF- 96 (200) silicone oil described in Evaluation No. 1.

EXAMPLE 3 A solution of 35.3 grams of BaCl,.2I-I 0 in 100 ml. of 7 water was added during 25 minutes and at about 30' C. to 25 grams of sodium cyanurate dissolved in 500 ml. of water. The resulting slurry was vacuum filtered and washed with water and then with two 100 ml. portions of ethanol. The resulting barium cyanurate was air-dried and then heated for 12 hours at 75 F. in a hot-air oven.

Upon admixture of 10 grams of the dried barium cyanurate'with 40 grams of SF96(200) silicone oil a grease having a penetration range of 320-330 mm./10 was obtained.

EXAMPLE 4 Calcium cyanurate was prepared by adding 13 grams of 98% CaCl,, dissolved in 100 ml. of water, to a tion of 25 grams of sodium cyanurate in 500 ml. of water and recovering and drying the precipitate as deg A solution of 20.8 grams of zinc chloride in ml. of water was prepared and added to a solution of 25 grams of sodium cyanurate in 500ml. of water. The resulting precipitate of zinc cyanurate was recovered and dried by the procedure described in Example 3. When a 10 gram sample of the zinc cyanurate was mixed uniformly with 40 grams of SF-96(200) silicone oil a thickened grease was formed which had a penetration range of 330-345 mm./l0.

Although several specific examples of the inventive concept have been described, the same should not be construed as limited thereby nor to the specific substances mentioned therein but to include various other compounds of equivalent constitution as set forth in the claims appended hereto. It is understood that any suitable changes, modifications and variations may be made without departing from the spirit and scope of the invention.

This is a continuation-in-part of our copending application Serial No. 559,107 filedt lanuary 16, 1956, now abandoned.

What we claim is:

1. A grease composition comprising a major proportion of an oil and, as a thickening agent therein, a minor quantity within the range of from about 3 to about 20 percent by weight of a salt of cyanuric acid. V

2. A grease composition as defined in claim 1 wherein the oil is as petroleum hydrocarbon mineral oil.

3. A greasecomposition as defined in claim 1 wherein the oil is a polyglycol synthetic lubricant.

4. A grease composition as defined in claim 1 wherein the oil is an ester synthetic lubricant.

5.Agreasecompositionasdefinedinclaim 1 wherein the oil is a silicone oil. i

6. A grease composition as defined in claim 1 wherein the salt of cyanuric acid is an alkali metal salt.

7. Agreasecompositionasdefinedinclaim 1 wherein the salt of cyanuric acid is a sodium salt.

8. A grease composition as defined in claim 1 wherein thesaltofeysnuricaeidisazincsalt.

9.Agreaseeompositionasdetinedinclaim1wherein the saltof cyanuric acid is an alkaline earth metal salt.

10. A grease composition comprising a major proportion of an oil and, as a thickening agent therein, a minor quantity within the range of from about 7 to about 12 percent by weight of a salt of cysnuric acid.

No references cited. 

1. A GREASE COMPOSITION COMPRISING A MAJOR PROPORTION OF OIL AND, AS A THICKENING AGENT THEREIN, A MINOR QUANTITY WITHIN THE RANGE OF FROM ABOUT 3 TO ABOUT 20 PERCENT BY WEIGHT OF A SALT OF CYANURIC ACID. 